1. Field of the Invention
The present invention relates to a semiconductor device including an oxide semiconductor and a method for manufacturing the semiconductor device.
In this specification, a semiconductor device generally means a device which can function by utilizing semiconductor characteristics, and an electrooptic device, a semiconductor circuit, and electronic equipment are all semiconductor devices.
2. Description of the Related Art
In recent years, a technique in which a thin film transistor (also referred to as TFT) is formed using an oxide semiconductor and is applied to an electronic device and the like has attracted attention. For example, a technique for forming a switching element of an image display device and the like using zinc oxide or an In—Ga—Zn—O based oxide semiconductor as an oxide semiconductor film is disclosed.
A typical technique for processing an oxide semiconductor is etching treatment. A technique for performing dry etching on an oxide semiconductor layer and a conductive layer covering the oxide semiconductor layer is disclosed in Patent Document 1.
In addition, a technique for performing dry etching on a conductive film containing SnO2, In2O3, or ZnO as a main component with the use of hydrogen iodide has been disclosed in Patent Document 2.